Move common authenticators code to a separate file.

Pulled code common between V1AuthenticatorTest and V2AuthenticatorTest 
to a separate file. It will be later used for NegotiatingAuthenticator 
unittest.

BUG=105214


Review URL: http://codereview.chromium.org/9285022

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@119001 0039d316-1c4b-4281-b951-d872f2087c98
5 files changed